EurekAlert! -- A research team at Vanderbilt University has developed an innovative optical system to simultaneously image electrical activity and metabolic properties in the same region of a heart, to study the complex mechanisms that lead to sudden cardiac arrest. Tested in animal models, the system could dramatically advance scientists’ understanding of the relationship between metabolic disorders and heart rhythm disturbances in humans that can lead to cardiac arrest and death, and provide a platform for testing new treatments to prevent or stop potentially fatal irregular heartbeats, known as arrhythmias.